FIG. 1 shows a can opener 10 of the prior art cutting the lid of a can 12. More particularly, the can opener typically comprises a toothed driving wheel 14 and a sharp cutting wheel 16. As shown in FIG. 1, the driving wheel 14 is rotated by a shaft 18 about an axis. In this example, the driving wheel 14 is driven in a anti-clockwise direction, as indicated by the arrow 20. The means for driving the driving wheel 14 is not shown, and typically comprises a hand crank or an electric motor.
The can 12 comprises a cylindrical, metal body portion 22, which is closed at the bottom 24 and open at the top. The can also includes a lid 26 which closes the open top of the body portion 22. As shown in FIG. 1, the lid 26 is formed of a disc-like piece of metal of larger diameter than the body portion 22, and is folded over the top of the body portion to form an annular lip 28 about the top of the body portion 22. A portion 29 of the lid 26 embraces the inner surface of the can wall (body portion) 22, and a central region 30 of the lid 26 is recessed within the top of the body portion 22.
The lip 28 includes a base portion 32 which, when using the can opener, cooperates with and is driven by teeth 34 on the driving wheel 14 to rotate the can with respect to the can opener. The lip 32 of the lid 26 is firmly retained against the teeth 34 of the driving wheel by a downward pressure exerted by the cutting wheel 16. In use, the cutting wheel 16 is introduced in a downward direction, indicated by the arrow 36, onto the lid 26 at the extreme periphery of the recessed region 30. Further downward pressure causes the cutting wheel to pierce (not shown) the lid, generally separating the recessed region 30 from the remainder thereof.
The cutting wheel 16 includes an inner face 38 and an outer face 40, which form a cutting edge 42 about the periphery of the cutting wheel. The cutting wheel 16 is mounted to a shaft 43, and is free to rotate, or is driven, in a clockwise direction, indicated by the arrow 44.
As the driving wheel turns, the can rotates and the cutting wheel rotates and continues to pierce the periphery of the recessed lid region until the recessed lid region separates from the remainder of the lid. The top of the can is thus opened to empty its contents.
It is also known that the cutting element, shown herein as a cutting wheel, can be a non-rotating element. Such a cutting element also pierces the lid of the can and continues to pierce the lid about its periphery as the driving wheel rotates the can with respect thereto.
The contents of the can are generally foodstuffs. Inevitably, some of the can contents adheres to the inner and outer faces 38, 40 of the cutting wheel. Hence, the cutting wheel has been called the "dirtiest square inch" in the kitchen. Prior art techniques of removing latent foodstuff from the cutting wheel include manually scrubbing the cutting wheel with a sponge or a toothbrush. These techniques are fairly adequate for cleaning the outer face 40 of the cutting wheel, but are not satisfactory for cleaning the more difficult to reach inner face 38 of the cutting wheel.
The present invention is applicable to any can opener which is used for removing the entire lid of a can, versus the type of can opener which merely pierces the lid of a can, such as for drinking its fluid contents.